Bringing a complex set of legacy code into a modern IDE like Eclipse doesn't necessarily require a huge amount of effort or retooling, if you can take advantage of an existing build process. Using Ant as an adaptor between the Eclipse IDE and your existing build process probably won't take you much time. It also gives you access to all of the existing capabilities. It might even let you simplify things a little, such as the configure script example you saw earlier, and provide some extra documentation for your build process.
UNIX developers looking to move to a friendlier, graphical IDE from the traditional command-line environment can use Eclipse with their existing code. You've seen how to create an empty project and looked at how to import your code from the filesystem, zip archive, or from source control in a CVS repository. Then you used Ant to build a project that uses a hand-crafted makefile and another that generates its makefile through a configure script.
As this new article on IBM developerWorks demonstrates, by taking advantage of Eclipse's syntax highlighting, code completion, and other amenities provided by a top-notch IDE, developers can quickly become more productive with their own code and others.